אַלְבִּ֥ישׁ שָׁמַ֖יִם קַדְר֑וּת וְשַׂ֖ק אָשִׂ֥ים כְּסוּתָֽם׃ (ס)
I clothe the heavens with blackness, And I make sackcloth their covering.
Read Jewish philosophy on Isaiah 50:3: Rambam's Guide for the Perplexed, Saadia Gaon, and classical Jewish philosophical sources, free online.